Materials of Construction - Metals - Alloy G-30
September 29, 2004

Introduction Chemical Composition Corrosion Resistance Physical Properties Mechanical Properties Fabrication         Heat Treatment         Forming         Welding

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Introduction

Hastelloy® alloy G-30 (UNS N06030) is a high chromium nickel-base alloy which shows superior corrosion resistance over most other nickel and iron-base alloys in commercial phosphoric acids as well as many complex environments containing highly oxidizing acids such as nitric/hydrochloric, nitric/hydrofluoric and sulphuric acids.

The resistance of alloy G-30 to the formation of grain boundary precipitates in the heat-affected zone makes it suitable for use in most chemical process applications in the as-welded condition.

Chemical Composition (%)

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Corrosion Resistance

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Physical Properties

Density	21°C (70°F)	8220 kg/m³ (513.2 lb/ft³)
Thermal Conductivity	100°C (212°F) 300°C (572°F) 500°C (932°F)	11.9 W/m K (83 BTU in/ft² h °F) 16.7 W/m K (116 BTU in/ft² h °F) 20.3 W/m K (141 BTU in/ft² h °F)

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Mechanical Properties

(Plate, 6.4 mm (0.250 in.) thick)
(Room Temperature)
(Solution heat-treated at 1177°C, rapid air cooled or water quenched)

Ultimate Tensile Strength	675.7 MPa (98 ksi)
Elongation in 50.8 mm (2 in.)	55%
Yield Strength (0.2% offset)	317.2 MPa (46 ksi)

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Fabrication

Heat Treatment

Wrought forms of alloy G-30 are furnished in the solution heat-treated condition unless otherwise specified.  The standard solution, heat-treatment consists of heating to 1177°C (2150°F) followed by rapid air-cooling or water quenching.  Parts that have been hot formed should be solution heat-treated prior to final fabrication or installation.

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Forming

Alloy G-30 has excellent forming characteristics and cold forming is the preferred method of forming.  Because of its good ductility, it can be easily cold-worked.  The alloy is generally stiffer than the austenitic stainless steels.  Therefore, more energy is required during cold forming.

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Welding

Alloy G-30 is readily welded by Gas Tungsten Arc (GTAW), Gas Metal-Arc (GMAW) and Shielded Metal-Arc (covered electrodes), welding techniques.  Its welding characteristics are similar to those for Hastelloy alloy G-3.  Submerged-Arc welding is not recommended as this process is characterized by hih heat input to the base metal and slow cooling of the weld.

The joint surface and adjacent area should be thoroughly cleaned before welding.  All grease, oil, crayon marks, sulphur compounds and other foreign matter should be removed.

Matching composition filler metal is recommended for joining alloy G-30.  For gas-tungsten-arc and gas-metal-arc welding, Hastelloy alloy G-30 filler wire (ER NiCrMo-11; UNS N06030) is suggested.  For shielded-metal-arc welding, alloy G-30 covered electrodes (E NiCrMo-11; UNS W86030) are suggested.

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